What is the OPC Web Client?
The OPC Web Client is actually a suite of development components that consist of:
- a native .NET component (assembly)
- an ActiveX control (*.ocx)
- OPC Web Service
The .NET component and ActiveX component are bundled together and called the “OPCData.NET” components. If you add the OPC Web Service to this, then you have the OPC Web Client.
All 3 components share a common API shown in the diagram here:
Common Interface
A common interface means that you can create an application that is agnostic to the underlying transport that actually communicates to your OPC Server. This means that your application can be created so that it does not know the difference if it is using the COM/DCOM as the transport, or the XML based OPC Web Service.
Redundant Communications
Because you have the choice to use the binary (.NET or ActiveX) components or the OPC Web Service, you can create an application that dynamically switches between the two transports.
Applications that work in the plant, and across the internet!
Using these tools you can build scalability into you applications without even trying. A common problem with many OPC systems is their inability to operate over the internet because of COM/DCOM security and the need to open your firewalls, or significant investments in Virtual Private Networking (VPN) technology to provide secure communications. By switching your application to utilize the OPC Web Service when operating remotely, you can gain access to your OPC Server(s) from across the internet. Using standard security capabilities built into IIS, such as Integrated Security and SSL technology, your communications via the internet can be secure.
|
